Motor problems, need help

so the stroker motor is done but things arent running right. the timing is on but for some reason it still wont run right. its a 4.0 stroked to a 4.6 and followed a lot of the write ups that are online. here is how its been working....


you can start it no problem and the idle is smooth but if you try to give it any gas it knocks and sputters slowly,when you let it go back to idle after that it dies. if you let it sit there and idle for a little bit it will die too. but wait theres more...

if you start it and while its idling, you disconnect the line to the brake booster and the line to the pvc valve from the manifold you can rev it up but the idle is high, like 1.5k - 2k rpms. and doesnt last very long and dies.

the motor runs rich no matter what.


so the question is, does anyone have any ideas as to what the problem could be with it. we're checking vaccum lines, replacing the bad O2 sensor and replacing the plug for the water temp sensor tomorrow. but if those dont fix it anyone else have ideas? let me know if you need more details.....

specs on the motor would be helpful, but it sounds like timing is off

bored .030 over
9.75:1 compression
4.2 crank and rods
204*/216* durration cam - comp cams #753901
millin high volume oil pump
ford 24 lbs/hr injectors
adj fuel pressure regulator
ported n polished head
k&n intake
2000 intake manifold
power aid throttle body spacer
2.5" exhaust

not much more i can think of. valves are still stock. the timing is on.

oh actually the stock injectors are in it now when its running rich. it ran way too lean when we put the 24 lbs/hr injectors in.

if i have enough time tomorrow or possibly this weekend i will try to take some video of how it runs and if i can find a place to host it you can see what its doing

What do you have the fuel pressure set at (vacuum disconnected from regulator)?
Check the vacuum line from MAP sensor to manifold and make sure it isn't cracked/broken. You can also check the voltage from the middle wire coming from the MAP sensor with the engine idling. It should be ~2.3v with the Crane 753901 cam (16inHg vacuum at idle).
The O2 sensor could also be faulty so check the voltage from the signal wire with the engine idling. Since the engine's running rich, it should read close to 1.0v if the sensor's working properly.

You do know the timing is not set from the distributor, right? If the timing, which is set by the CPS, is on, check to make sure the distributor is indexed properly. If it's not, it throws off the fuel injection synchronization.

I am having the same problem with my 87, but does your tach dance all over the place?